Haley is a rising star in national Republican circles and a tea party favorite. But at home, the first-term governor has struggled politically, fighting with Republicans in the Legislature and others in the party while enjoying lackluster support from independent voters. Haley appears safe from a primary challenge, but some polls have suggested that she could be vulnerable in the general election, despite the state's strong conservative bent.

The Senate appointment could help Haley address some of these challenges, GOP operatives based in South Carolina and others with strong ties to the state said she is likely to take full advantage of the opportunity as she considers from a narrowed pool of five potential candidates. CNN first reported who was on the short list Tuesday, and each candidate carries strengths and weaknesses.

Rep. Trey Gowdy: Gowdy has tea party and conservative bona fides. He is not perceived to be personally close to Haley. Per one knowledgeable South Carolina-based GOP operative, Gowdy is the "unlikely choice for Haley, but for a future U.S. Senate race, a very good candidate." Another source added that the Gowdy mention on the list might have as much to do with poking Rep. Mick Mulvaney, R-S.C., as pushing Gowdy. Haley and Mulvaney have an adversarial relationship.

Former state Attorney General Henry McMaster: He is close to Haley and was an early backer of her 2010 gubernatorial bid. He is said to be a solid conservative but he is of the old school party establishment, not the tea party. That makes him vulnerable when running for election in 2014. "He is a safe choice for Haley who won't overshadow her in state politics," said the knowledgeable South Carolina-based GOP operative.

"There is no real downside, no real upside," echoed another.

Former South Carolina First Lady Jenny Sanford: The notion of Sanford has left many scratching their heads. The consensus is that at the outset, she would be the most appealing option to the largest swath of South Carolinians. Sanford is a sentimental favorite in light of her husband, former GOP Gov. Mark Sanford's personal scandal. She was also an early Haley backer during the 2010 gubernatorial campaign.

But nearly every operative said that long term, she is a risky option and one went so far as to call her a political and policy "wildcard." Some Palmetto State GOP insiders have described her personality as difficult.

Rep. Tim Scott: Since DeMint announced his plans to resign, Scott has been the candidate at the center of the most speculation. It is agreed that he would be the most help to Haley, politically, in 2014. Scott would please the GOP and tea party base and as an African-American, he would be a strategically smart and historic choice. But media speculation does not always translate to an outcome (just ask Caroline Kennedy). As one source put it, "When the decision is made by a committee of one, there’s no such thing as a frontrunner."

Director of the state Department of Health and Environmental Control Catherine Templeton: Templeton is the least known on the list. She is a member of Haley's cabinet and is said to be personally very close to the governor. One operative said that her name surfacing on the list is just random enough that it must be serious.

But if she is the pick, Templeton will have to build a statewide political apparatus at light speed to prepare for 2014. She is said to be instantly vulnerable in a GOP primary because of her lack of name identification. That has implications for Haley. It will hurt the governor politically if Templeton does not get through a primary. But also, operatives say Haley might need help in the general election and Templeton would not have a lot to offer the governor in the form of coattails.